3Ni,Y.J.,&Zhou,Y.D.(2005).Teaching and learning fraction and rational numbers:The origins and implications of whole number bias.Educational Psychologist,40,27-52.
4Mack, N.K., Learning fractions with understanding: building on informal knowledge[J].Journal for Research in Mathematics Education.1990,21(1) : 16-32.
5Cramer,K.A.,Pest,T.R.,& delMas R.C..Initial fraction learning by fourth-and fifth-grade students: A comparison of the effects of using commercial curricula with the effects of using the rational number project curriculum [J] ,Journal for Research in Mathematics Education, 2002,33 (2) : 111-144.
